Myriophyllum aquaticum
Midwest Noxious Weed: Do Not Plant
Common Name: parrot feather water milfoil 
Type: Herbaceous perennial
Family: Haloragaceae
Native Range: South America, Australia, New Zealand, Java
Zone: 6 to 10
Height: 0.25 to 0.50 feet
Spread: 0.50 to 1.00 feet
Bloom Time: July to August
Bloom Description: Yellowish-green
Sun: Full sun to part shade
Water: Wet
Maintenance: Medium
Suggested Use: Water Plant, Naturalize, Rain Garden
Flower: Insignificant
Attracts: Birds
This plant is listed as a noxious weed in one or more Midwestern states outside Missouri and should not be moved or grown under conditions that would involve danger of dissemination.

Culture

Winter hardy to USDA Zones 6-10. In water gardens, grow in containers submerged in up to 6” of water or on wet banks. Also may be grown in the shallow margins of a pond. Best in organically rich soils in full sun to part shade. Thin clumps as needed. Cuttings will root easily. Cut stems back below water line in fall. Foliage dies back to the rhizomes in winter.

Noteworthy Characteristics

Myriophyllum aquaticum, commonly called parrot’s feather or diamond milfoil, is a rhizomatous aquatic perennial that has both submerged and emergent feathery leaves that appear in whorls along the stems. Stems can grow to 6’ long. Submerged foliage is chartreuse. Emergent foliage is dark blue green. Emergent stems trail to shoreline and will root in the banks, making this a good transitional plant for margins of water gardens or ponds. Tiny yellowish-green flowers bloom in summer from the leaf axils of emergent stems. Submerged foliage serves as shelter for fish, helps remove excess nutrients and acts as an oxygenator. Native to South America, Australia and New Zealand, this plant has escaped cultivation and has naturalized throughout much of North America.

Genus name comes from the Greek words myrios meaning many and phyllon meaning a leaf with reference to the many divisions of the submerged leaves.

Specific epithet means growing in or near water.

Problems

No serious insect or disease problems. Can spread invasively in natural ponds when winter hardy.

Uses

Transitional plant for water gardens and ponds.